Jump to content
Alexei

weight difference with plastic and carbon

Recommended Posts

i am playing with the idea of getting a few carbon parts for my rc car, to make it a little bit lighter (and to have something new happen). im not in need of the extra stiffness, but mostly after weight reduction.

so question is, how much lighter is carbon/graphite compared to plastic? i know we arent talking big savings like complared to steel, but compared to plastic it is still lighter, i take? im asking because i dont want to spend the money only to find out no weight was saved.

 

Share this post


Link to post
Share on other sites

It is difficult to make a generalisation, because while carbon (or strictly, carbon-reinforced plastic) is stronger than plastic on its own, this strength advantage can be used in different ways in different components, or even in different designs of the same component.

For example, some carbon parts are no lighter than their plastic counterparts, but are significantly stronger. Others are about the same as the plastic parts in terms of strength while being significantly lighter. Then there are some that are a bit lighter and a bit stronger.

Then there is stiffness versus resilience to consider. Carbon parts are stiff by nature, whereas plastic ones tend to be more flexible. In some cases this might actually mean that the plastic parts last longer as they can flex in an impact, as opposed to the carbon ones that would crack.

Which parts are you considering specifically, and which car are they going on?

  • Like 3

Share this post


Link to post
Share on other sites

the stock batteri holder is about 12,5g of weight. not sure what the carbon one would weigh. but i dont want to buy it if bling is all it is :)  

Share this post


Link to post
Share on other sites

Given that the MR-4TC SC dates from before the days of LiPo and was designed with heavier NiMH batteries in mind, I'd argue that you don't really want to save any weight on the battery side of the model, as it is already lighter than intended, and thus potentially unbalanced, assuming you are running it on LiPo of course. If anything, you are more likely to want to add weight on the battery side. But the carbon battery holder looks nice, so even if it is the same weight as the plastic one, you could argue for it on cosmetic grounds. If I'm honest, that is why my TT-02 Type S has a carbon battery holder...

The carbon shock towers would be stiffer than their plastic counterparts and thus make the car more responsive to setup changes involving the shocks and springs, so would be a good idea even if they don't save any weight.

  • Like 1

Share this post


Link to post
Share on other sites

Depends on how the carbon fibre parts are implemented... on a DF-03 the plastic chassis, battery plate & clip weigh 114g whilst the aftermarket (3Racing) carbon fibre & alloy chassis weighs in at 194g. That extra 80g has got to impact on performance!

Share this post


Link to post
Share on other sites
10 minutes ago, TurnipJF said:

Given that the MR-4TC SC dates from before the days of LiPo and was designed with heavier NiMH batteries in mind, I'd argue that you don't really want to save any weight on the battery side of the model, as it is already lighter than intended, and thus potentially unbalanced, assuming you are running it on LiPo of course. If anything, you are more likely to want to add weight on the battery side. But the carbon battery holder looks nice, so even if it is the same weight as the plastic one, you could argue for it on cosmetic grounds. If I'm honest, that is why my TT-02 Type S has a carbon battery holder...

The carbon shock towers would be stiffer than their plastic counterparts and thus make the car more responsive to setup changes involving the shocks and springs, so would be a good idea even if they don't save any weight.

actually im still running NiMH batteri in it. but i didnt think of the weight balance. i did for a short while think of changing to brushless and LiPo. in any case, its the shock towers that has priority.

 

3 minutes ago, martinjpayne said:

Depends on how the carbon fibre parts are implemented... on a DF-03 the plastic chassis, battery plate & clip weigh 114g whilst the aftermarket (3Racing) carbon fibre & alloy chassis weighs in at 194g. That extra 80g has got to impact on performance!

yeah, thats what i want to avoid. i do have installed some other lightweight saving parts, and i have weighted to see how much i save (but may not be 100% accurate).

screws: stock 50 g --> titanium 27 g

shaft drive:  stock aluminium 14 g --> graphite 7 g

input shafts: stock steel 10.24 g --> aluminium 4 g

spur gear holder: stock 4,3 g --> aluminium 3 g

bell crank post: stock brass 2,4 g --> aluminium 0 g (too light to get the scale to weigh it. have since then gotten a small scale to weigh spices)

Share this post


Link to post
Share on other sites

Agree with @TurnipJF

There are way more experienced racers than me in here but fwiw:

1. Making shock towers more responsive should come after some sums looking at resultant droop, camber and steering link rigour / response ... or you’ll bounce around like a moon buggy, not be able to recover  + get v annoyed 🙄

2. Understanding the domino effect of what will break first elsewhere should really even come before 1  - because you’ll (again) get frustrated at an early bath when practising or get pushed hard + quickly by racers who will sacrifice power in their packs to take you out ...

3. Its worth using the weight you save elsewhere ... because anyone purely increasing power to weight ends up with an expensive and uncompetitive crash ☹️

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...